KR20180099048A - Heat pump system for vehicle - Google Patents

Abstract

Provided is a vehicular air conditioning system capable of simultaneously performing a dehumidifying effect by causing a low-temperature and low-pressure refrigerant to flow toward an indoor heat exchanger while performing coolant heating through refrigerant heat by using a water heating condenser. The vehicular air conditioning system includes a compressor compressing and discharging a refrigerant; an indoor heat exchanger provided inside an air conditioning case for heat exchange between air and the refrigerant; an outdoor heat exchanger installed outside the air conditioning case for heat exchange between outside air and the refrigerant; a heater core provided inside the air conditioning case for heat exchange between air and a coolant; first expansion means provided between the indoor heat exchanger and the outdoor heat exchanger for refrigerant expansion; a chiller for heat exchange between vehicular waste heat and the refrigerant; a water-cooled condenser for heat exchange between the refrigerant discharged from the compressor and the coolant of a coolant line flowing through the heater core; a first refrigerant circulation line connecting a refrigerant line such that the refrigerant discharged from the compressor circulates through the outdoor heat exchanger, the first expansion means, the indoor heat exchanger, and the compressor; and a second refrigerant circulation line connecting a refrigerant line such that the refrigerant discharged from the compressor circulates through the water-cooled condenser, the chiller, and the compressor. A part of the refrigerant in the second refrigerant circulation line branches to the first refrigerant circulation line.

Description

{HEAT PUMP SYSTEM FOR VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle air conditioning system, and more particularly, to a vehicle air conditioning system capable of selectively performing cooling and heating by switching a flow direction of a refrigerant using one refrigerant cycle.

2. Description of the Related Art Generally, an air conditioner for a vehicle includes a cooling system for cooling the interior of a vehicle and a heating system for heating the interior of the vehicle. The cooling system exchanges the air passing through the outside of the indoor heat exchanger with the refrigerant flowing in the inside of the evaporator at the indoor heat exchanger side of the refrigerant cycle to cool the inside of the vehicle by changing the refrigerant. In addition, the heating system is configured to heat the interior of the vehicle by changing the air passing through the heater core from the heater core side of the cooling water cycle to the heat exchanged with the cooling water flowing inside the heater core.

On the other hand, a heat pump system which can selectively perform cooling and heating by switching the flow direction of refrigerant by using one refrigerant cycle is applied, unlike the above-described vehicle air conditioner. The heat pump system includes an indoor heat exchanger installed inside the air conditioner case for exchanging heat with air blown into the passenger compartment, an outdoor heat exchanger for exchanging heat outside the air conditioner case, and a direction control valve for switching the flow direction of the refrigerant Respectively. Therefore, when the cooling mode is operated according to the flow direction of the refrigerant by the direction control valve, the indoor heat exchanger functions as a cooling heat exchanger. When the heating mode is activated, the indoor heat exchanger functions as a heating heat exchanger .

On the other hand, in a hybrid vehicle driven by an engine (internal combustion engine) and an electric motor, engine waste heat (cooling water) is used as a heating heat source for indoor heating. That is, when the engine is driven, the waste heat of the engine is sufficient, so that the air conditioner can be used in the same manner as the existing vehicle in heating. However, even if the engine is turned off under the condition driven by the electric motor, . In the case of an electric motor driven condition, when the outside temperature is low (below about 0 ℃), the engine cooling water becomes insufficient and the engine cooling water becomes below a certain temperature, The engine is forcibly operated and the fuel efficiency of the hybrid vehicle is lowered.

Korean Patent Laid-Open Publication No. 10-2014-0126846 (Apr. 31, 2014) discloses a vehicular air conditioning system in which an evaporator in an air conditioning case is commonly used for cooling and heating in an air conditioning mode and a heat pump mode. FIG. 1 shows an air conditioning mode of a conventional automotive air conditioning system, and FIG. 2 shows a heat pump mode of a conventional automotive air conditioning system.

1 and 2, a conventional automotive air conditioning system is preferably applied to a hybrid vehicle, and includes a compressor 100, an evaporator 110, an outdoor heat exchanger 130, an expansion unit 120 , A chiller (140), a first refrigerant circulation line (R1), and a second refrigerant circulation line (R2).

The first refrigerant circulation line R1 constitutes a refrigerant line so that the refrigerant discharged from the compressor 100 in the air conditioning mode circulates through the outdoor heat exchanger 130, the expansion means 120, the evaporator 110 and the compressor 100 do. The second refrigerant circulation line R2 constitutes a refrigerant line in which the refrigerant discharged from the compressor 100 circulates through the evaporator 110, the expansion means 120, the chiller 140 and the compressor 100 in the heat pump mode .

The first refrigerant circulation line (R1) and the second refrigerant circulation line (R2) are configured to share a part of them in common. That is, a part of the first refrigerant circulation line R1 and the second refrigerant circulation line R2 are integrally formed and used in common, and the common sections a and b of the first and second refrigerant circulation lines R1 and R2, b is an interval a in which the compressor 100 is connected and a interval b in which the evaporator 110 and the expansion means 120 are connected. The outdoor heat exchanger 130 is provided in the first refrigerant circulation line R1 and the chiller 140 is provided in the second refrigerant circulation line R2.

The compressor 100 sucks the refrigerant, compresses it, and discharges it to the high-temperature, high-pressure gaseous state. The evaporator 110 is installed inside the air conditioning case 150 to exchange heat between the air flowing in the air conditioning case 150 and the refrigerant. The evaporator 110 acts as a natural evaporator 110 in the air conditioner mode to perform a cooling function, and functions as a condenser in a heat pump mode to perform a heating function.

The outdoor heat exchanger (130) is installed outside the air conditioning case (150) to exchange heat between the outdoor air and the refrigerant. The expansion means (120) is disposed between the evaporator (110) and the outdoor heat exchanger (130) to expand the refrigerant. The air conditioning case 150 is provided therein with a heater core 160 connected to the vehicle engine 161 through a cooling water circulation line W. The cooling water circulation line W is provided with a water pump 162 for circulating the cooling water of the engine 161 to the heater core 160 side.

Between the evaporator 110 and the heater core 160, there is provided a temperature control door 151 for controlling the amount of air passing through the heater core 160 and the amount of air passing through the heater core 160. The second refrigerant circulation line (R2) on the inlet side of the chiller (140) is provided with an on-off valve (183) which is closed in the air conditioning mode and opened in the heat pump mode. At the inlet side of the compressor 100, an accumulator 170 separating the liquid refrigerant and the gaseous refrigerant from the refrigerant flowing into the compressor 100 and supplying only the gaseous refrigerant is provided.

The refrigerant discharged from the compressor 100 is discharged to the first refrigerant circulation line R1 at the point where the first and second refrigerant circulation lines R1 and R2 are branched at the outlet side of the compressor 100 according to the air conditioning mode or the heat pump mode, Or a first direction switching valve 181 for switching the refrigerant flow direction so as to flow to the second refrigerant circulation line R2 side.

The first and second refrigerant circulation lines R1 and R2 are connected to each other at a position where the compressor 100 is connected to the evaporator 110 and the evaporator 110 and the expansion unit 120 are connected to each other, The refrigerant flow direction is switched so that the refrigerant discharged from the evaporator 110 flows toward the compressor 100 along the first refrigerant circulation line R1 at the point where the refrigerant is branched, Way switching valve 182 having a bidirectional three-way valve structure for switching the direction of the refrigerant flow so that the refrigerant flowing out of the first refrigerant circulation line (R2) flows to the evaporator 110 side.

Referring to FIG. 1, in the air conditioner mode in the engine off state, the first refrigerant circulation line 181, the second direction switching valve 182, and the on-off valve 183 are controlled by the first direction switching valve 181, the second direction switching valve 182, The refrigerant is circulated along the refrigerant line R1. The water pump 162 is stopped and the cooling water is not circulated to the heater core 160 and the chiller 140 side in the state where the engine 161 is off. The temperature control door 151 in the air conditioning case 150 closes the passage through the heater core 160 so that the air blown into the air conditioning case 150 by the blower passes through the evaporator 110 The heater core 160 is bypassed and supplied to the interior of the vehicle, thereby cooling the interior of the vehicle.

The gaseous refrigerant of high temperature and high pressure discharged after being compressed by the compressor 100 is supplied to the outdoor heat exchanger 130 through the first direction switching valve 181. The refrigerant supplied to the outdoor heat exchanger 130 is heat-exchanged with the outside air to be condensed, and the gaseous refrigerant is converted into the liquid refrigerant. Subsequently, the refrigerant having passed through the outdoor heat exchanger 130 is expanded and decompressed in the course of passing through the expansion means 120, and is converted into low-temperature low-pressure liquid refrigerant, and then flows into the evaporator 110. The refrigerant flowing into the evaporator 110 is heat-exchanged with the air blown into the air conditioning case 150 through the blower to evaporate, and at the same time, the air is cooled by an endothermic effect due to the latent heat of evaporation of the refrigerant. And is supplied to the room for cooling. Then, the refrigerant discharged from the evaporator 110 flows into the compressor 100 through the second direction switching valve 182, and repeats the above-described cycle.

2, when the engine is in the OFF state and the heat pump mode is selected, the first and second directional control valves 181, 182 and 183 control the second refrigerant circulation The refrigerant is circulated along the line R2. In the OFF state of the engine 161, the cooling water is not circulated to the heater core 160 and the chiller 140, but the cooling water may be circulated when the water pump 162 is operated. In addition, when the engine 161 is in the OFF state, the residual heat remaining in the cooling water of the engine 161 is used as a heating heat source. The temperature control door 151 in the air conditioning case 150 is operated to close the passage bypassing the heater core 160 so that the air blown into the air conditioning case 150 by the blower is supplied to the evaporator 110 Heating function) and is supplied to the interior of the vehicle, thereby heating the interior of the vehicle.

The gaseous refrigerant of high temperature and high pressure discharged after being compressed by the compressor 100 is supplied to the evaporator 110 through the first direction switching valve 181 and the second direction switching valve 182. The high-temperature, high-pressure gaseous refrigerant supplied to the evaporator 110 is heat-exchanged with air flowing in the air conditioning case 150 to be condensed and simultaneously heats the air, and the heated air is supplied to the vehicle interior to be heated. Subsequently, the refrigerant having passed through the evaporator 110 is expanded and decompressed in the process of passing through the expansion means 120 to become a low-temperature and low-pressure liquid-phase refrigerant, and then flows into the chiller 140. The refrigerant flowing into the chiller 140 evaporates while exchanging heat with the cooling water (engine waste heat) of the engine 161. Then, the refrigerant discharged from the evaporator 110 flows into the compressor 100, and repeats the cycle as described above.

The conventional automotive air conditioning system recovers the engine cooling water heat source and has an indoor heating effect. The indoor heat exchanger radiates the refrigerant heat and uses it as heating heat. In addition, the waste heat of the engine is recovered through the chiller and used as the refrigerant vaporization energy.

However, in the conventional automotive air conditioning system of the related art, when the heat pump is operated, the temperature of the cooling water rapidly changes, and according to the cooling water temperature, there arises a condition that warm air passing through the indoor heat exchanger heats the cooling water flowing through the heater core. In addition, since the conventional automotive air conditioning system requires a separate high-pressure indoor heat exchanger, there is a problem that separate management is required for production and the production cost is increased.

On the other hand, the conventional automotive air conditioning system has a disadvantage that dehumidification can not be performed simultaneously in a heating cycle of approximately 0 ° C to 10 ° C. That is, there is a problem that the power consumption of the air conditioner increases as the heating is performed by using the high voltage PTC heater while driving the cooling cycle.

Korean Patent Publication No. 10-2014-0126846 (Apr. 31, 2014)

In order to solve such a conventional problem, in the present invention, the cooling water is heated through the refrigerant heat using the water-heating condenser, and the low-temperature and low-pressure refrigerant flows into the indoor heat exchanger, System.

A vehicle air conditioning system according to the present invention includes: a compressor for compressing and discharging a refrigerant; An indoor heat exchanger provided inside the air conditioning case for exchanging heat between air and refrigerant; An outdoor heat exchanger installed outside the air conditioning case for exchanging heat between the outside air and the refrigerant; A heater core provided inside the air conditioning case for exchanging heat between air and cooling water; A first expansion means provided between the indoor heat exchanger and the outdoor heat exchanger to expand the refrigerant; A chiller for exchanging heat between the waste heat of the vehicle and the refrigerant; A water-cooled condenser for exchanging heat between the refrigerant discharged from the compressor and the cooling water in the cooling water line flowing through the heater core; A first refrigerant circulation line connecting the refrigerant line to circulate the refrigerant discharged from the compressor through the outdoor heat exchanger, the first expansion means, the indoor heat exchanger, and the compressor; And a second refrigerant circulation line connecting the refrigerant line to circulate the refrigerant discharged from the compressor to the water-cooled condenser, the chiller, and the compressor, wherein a part of the refrigerant in the second refrigerant circulation line branches to the first refrigerant circulation line do.

The second expansion means is provided in the second refrigerant circulation line between the water-cooled condenser and the chiller to expand the refrigerant. The second expansion means is branched from the second refrigerant circulation line on the downstream side of the second expansion means and flows to the chiller side And a refrigerant branch line that flows at least a part of the refrigerant toward the indoor heat exchanger.

The refrigerant flow control valve selectively controls the amount of the refrigerant flowing toward the refrigerant branch line.

In the above, the refrigerant branch line is branched between the second expansion means and the chiller, and is connected to the first refrigerant circulation line between the first expansion means and the indoor heat exchanger.

In the above, the refrigerant branch line is connected upward from the second refrigerant circulation line.

In the above, a first cooling water line, which is a passage through which the engine of the vehicle and the chiller are connected to cool the cooling water; A second cooling water line connected to the first cooling water line for selectively passing or bypassing the first cooling water line and circulating the heater core; And a four-way valve for connecting the first cooling water line and the second cooling water line. The cooling water passing through the heater core passes or passes through the chiller and the engine according to the operation of the four-way valve.

In the above, the second cooling water line is provided with a heating means for heating the cooling water.

The refrigerant discharged from the compressor is caused to flow to the first refrigerant circulation line or the second refrigerant circulation line side in accordance with the cooling mode or the heating mode at the point where the first and second refrigerant circulation lines are branched at the outlet side of the compressor, A direction switching valve for switching the direction is provided.

The automotive air conditioning system according to the present invention can reduce the air conditioning consuming power by branching the refrigerant in the low pressure portion to the side of the chiller and the indoor heat exchanger without operating the high voltage PTC and the compressor even in the heating mode operation, By forming the upper portion of the refrigerant branching direction by branching upward from the refrigerant circulation line, it is possible to prevent the oil circulating through the refrigerant line from accumulating in the branch line.

1 shows an air conditioning mode of a conventional automotive air conditioning system,
2 shows a heat pump mode of a conventional automotive air conditioning system,
FIG. 3 illustrates a vehicle air conditioning system according to an embodiment of the present invention,
4 is an enlarged cross-sectional view of a refrigerant branch line of a vehicle air conditioning system according to an embodiment of the present invention,
5 illustrates a cooling mode of a vehicle air conditioning system according to an embodiment of the present invention,
6 is a view illustrating a heating heat pump mode of a vehicle air conditioning system according to an embodiment of the present invention,
FIG. 7 illustrates a heating heat pump mode and a dehumidifying mode of a vehicle air conditioning system according to an embodiment of the present invention.

Hereinafter, the technical configuration of the air conditioning system for a vehicle will be described in detail with reference to the accompanying drawings.

3 shows a vehicle air conditioning system according to an embodiment of the present invention.

3, a vehicle air conditioning system according to an embodiment of the present invention is applied to a hybrid vehicle, and includes a compressor 700, an indoor heat exchanger 710, an outdoor heat exchanger 730, A first cooling water line 704, a second cooling water line, a water-cooled condenser 800, a first refrigerant circulation line 701, and a second refrigerant circulation line 702. The core 760, the first expansion means 720, the chiller 740, And a second refrigerant circulation line 702.

The compressor 700 sucks the refrigerant, compresses it, and discharges it into a gas state of high temperature and high pressure. The indoor heat exchanger 710 is provided inside the air conditioning case 750 to exchange heat between the air flowing in the air conditioning case 750 and the refrigerant. The outdoor heat exchanger 730 is provided outside the air conditioning case 750 to exchange heat between the outdoor air and the refrigerant. The heater core 760 is provided inside the air conditioning case 750 to exchange heat between the air flowing in the air conditioning case 750 and the cooling water. The first expansion means 720 is disposed between the indoor heat exchanger 710 and the outdoor heat exchanger 730 to expand the refrigerant.

A temperature control door 751 is provided in the air conditioning case 750 between the indoor heat exchanger 710 and the heater core 760 to regulate the amount of air bypassing the heater core 760 and the amount of air passing therethrough, . The chiller 740 exchanges heat between the waste heat of the vehicle and the refrigerant. At the inlet side of the compressor 700, an accumulator 770 for separating the liquid refrigerant and the gaseous refrigerant from the refrigerant flowing into the compressor 700 and supplying only the gaseous refrigerant is provided.

The first cooling water line 704 connects the engine 761 of the vehicle with the chiller 740 to circulate the cooling water. Although the second cooling water lines 703 and 705 are shown with reference numerals 703 and 705 for the sake of convenience of description, the first cooling water lines 703 and 705 substantially correspond to the first cooling water lines 703 and 705, , And the downstream line is divided into 705. [ The second cooling water lines 703 and 705 are connected to the first cooling water line 704 to selectively pass or bypass the first cooling water line 704 and circulate the heater core 760.

The water-cooled condenser 800 is provided in the second cooling water line on the upstream side of the heater core 760 in the flow direction of the cooling water. The water-cooled condenser 800 exchanges heat between the refrigerant discharged from the compressor 700 and the cooling water flowing through the second cooling water line.

The first refrigerant circulation line 701 circulates the refrigerant discharged from the compressor 700 through the outdoor heat exchanger 730, the first expansion device 720, the indoor heat exchanger 710, and the compressor 700 in the cooling mode. A refrigerant line is connected to the refrigerant line. The second refrigerant circulation line 702 connects the refrigerant line to circulate the refrigerant discharged from the compressor 700 through the water-cooled condenser 800, the chiller 740, and the compressor 700 in the heat pump mode. A portion of the refrigerant in the second refrigerant circulation line 702 branches to the first refrigerant circulation line 701.

A direction switching valve 781 is provided at a point where the first and second refrigerant circulation lines 701 and 702 are branched at the outlet side of the compressor 700. The directional control valve 781 switches the refrigerant flow direction so that the refrigerant discharged from the compressor 700 flows toward the first refrigerant circulation line 701 or the second refrigerant circulation line 702 in the cooling mode or the heating mode. The directional control valve 781 is preferably constituted by a three-way valve.

A four-way valve 706 is provided at a connection point between the first cooling water line 704 and the second cooling water line 703, 705. The four-way valve 706 connects the first cooling water line 704 and the second cooling water line 703 and 705. When the four-way valve 706 operates, the cooling water passing through the heater core 760 flows through the chiller 740 And the engine 761 or bypasses the chiller 740 and the engine 761. And the second outdoor heat exchanger 735 is connected to the engine 761 through a separate cooling line 736. [

The second refrigerant circulation line 702 is provided with a second expansion means 721 between the water-cooled condenser 800 and the chiller 740. In this case, it is preferable that the first expansion means 720 is an expansion valve driven by a mechanical or an electronically, and the second expansion means 721 is a unidirectional orifice.

In addition, the second cooling water lines 703 and 705 are provided with a heating means 810 for heating the cooling water. The heating means 810 may be a PTC heater and is preferably provided between the water-cooled condenser 800 and the heater core 760. The first cooling water line 704 is provided with a first water pump 707 for circulating cooling water, and the second cooling water line is provided with a second water pump 708 for circulating cooling water.

The air conditioning system for a vehicle according to an embodiment of the present invention includes a refrigerant branch line 910. The refrigerant branch line 910 is branched at the second refrigerant circulation line 702 downstream of the second expansion means 721 so that at least a part of the refrigerant flowing toward the chiller 740 is selectively supplied to the indoor heat exchanger 710 side Flow.

In addition, the vehicle air conditioning system according to an embodiment of the present invention includes a refrigerant flow rate control valve 920. The refrigerant flow control valve 920 selectively controls the amount of refrigerant flowing toward the refrigerant branch line 910 side. The refrigerant flow control valve 920 may be a two-way valve or a three-way valve and may be provided on the refrigerant branch line 910.

The refrigerant branch line 910 is connected to the refrigerant line between the second expansion means 721 and the compressor 700 and the front end of the indoor heat exchanger 710. More specifically, the refrigerant branch line 910 is branched between the second expansion means 721 and the chiller 740 and flows through the first refrigerant cycle 710 between the first expansion means 720 and the indoor heat exchanger 710 Line 701, respectively. The refrigerant flowing through the second refrigerant circulation line 702 through the water-cooled condenser 800 is directed to the chiller 740 after passing through the second expansion means 721. A part of the refrigerant flows through the refrigerant flow rate control valve 920, The refrigerant flows into the indoor heat exchanger 710 without flowing into the chiller 740 by the opening / closing operation of the first expansion means 720.

The refrigerant flowing through the second refrigerant circulation line 702 expands at a low pressure through the second expansion means 721 and the refrigerant expanded at the low pressure passes through the refrigerant branch line 910 and passes through the indoor heat exchanger 710 Exchanges heat with the air in the air conditioning case 750 and condenses the moisture in the air on the surface of the indoor heat exchanger 710. As a result, the air-conditioning air discharged into the passenger compartment generates a dehumidifying effect.

At the same time, the refrigerant expanded at a low pressure through the second expansion means 721 flows toward the chiller 740 side. In this case, the refrigerant flow rate control valve 920 is provided in the refrigerant branch line 910 so that the refrigerant always flows toward the chiller 740 and only a part of the refrigerant directed toward the chiller 740 flows through the refrigerant branch line 910 To the heat exchanger 710 side.

That is, the refrigerant flowing through the second expansion means 721 always flows toward the chiller 740 but does not necessarily flow toward the indoor heat exchanger 710 through the refrigerant branch line 910. The refrigerant flow rate control valve 920 is completely closed so that the refrigerant flow control valve 920 can control all the refrigerant to flow only to the chiller 740 side.

4 is an enlarged sectional view of a refrigerant branch line of the air conditioning system for a vehicle according to an embodiment of the present invention. Referring to FIG. 4, the refrigerant branch line 910 is connected upward from the second refrigerant circulation line 702. In this case, the upper direction is the height direction. Therefore, when the dehumidifying mode is not used, oil trapping to the dehumidifying line can be prevented.

The vehicle air conditioning system according to an embodiment of the present invention may include cooling water temperature sensing means for sensing the temperature of the cooling water. The control unit of the air conditioning system of the vehicle performs the heating heat pump mode when the sensed temperature of the cooling water is lower than the reference temperature and performs the heating and cooling water mode when the sensed temperature of the cooling water is higher than the reference temperature.

In the heating heat pump mode, the refrigerant discharged from the compressor 700 circulates through the water-cooled condenser 800, the chiller 740, and the compressor 700, and the second cooling water line bypasses the first cooling water line 704 The cooling water circulates through the water-cooled condenser 800, the heater core 760, and the water-cooled condenser 800. The cooling water of the first cooling water line 704 circulates engine 761, chiller 740, and engine 761 independently of the second cooling water line.

In the heating cooling water mode, the compressor 700 is stopped and the second cooling water line is connected to the first cooling water line 704 so that the cooling water is circulated through the water-cooled condenser 800, the heater core 760, the chiller 740, The engine 761, and the water-cooled condenser 800 are circulated.

5 illustrates a cooling mode of a vehicle air conditioning system according to an embodiment of the present invention.

Referring to FIG. 5, in the cooling mode, the refrigerant is circulated along the first refrigerant circulation line 701 under the control of the direction switching valve 781. The temperature control door 751 in the air conditioning case 750 closes the passage through the heater core 760 so that the air blown into the air conditioning case 750 by the blower flows into the indoor heat exchanger 710, The heater core 760 is bypassed and supplied to the interior of the vehicle, thereby cooling the interior of the vehicle.

The gaseous refrigerant of high temperature and high pressure discharged after being compressed by the compressor 700 is supplied to the outdoor heat exchanger 730 via the direction switching valve 781. [ The refrigerant supplied to the outdoor heat exchanger 730 is heat-exchanged with the outside air to be condensed, and the gaseous refrigerant is converted into liquid refrigerant. Subsequently, the refrigerant having passed through the outdoor heat exchanger 730 is decompressed and expanded in the process of passing through the first expansion means 720, and becomes the low-temperature and low-pressure liquid refrigerant, and then flows into the indoor heat exchanger 710.

The refrigerant flowing into the indoor heat exchanger 710 is heat-exchanged with the air blown into the air conditioning case 750 through the blower to evaporate, and at the same time, the air is cooled by an endothermic effect due to the latent heat of evaporation of the refrigerant. Is supplied to the interior of the vehicle and cooled. Thereafter, the refrigerant discharged from the indoor heat exchanger 710 flows into the compressor 700 through the accumulator 770, and repeats the above-described cycle.

In this case, the cooling water that has passed through the engine 761 passes through the water-cooled condenser 800, the heating means 810, the heater core 760, the four-way valve 706 through the chiller 740, Circulate.

6 illustrates a heating heat pump mode of the air conditioning system for a vehicle according to an embodiment of the present invention.

Referring to FIG. 6, when the cooling water temperature is relatively low, the refrigerant is circulated along the second refrigerant circulation line 702 under the control of the direction switching valve 781 when the heat pump mode is performed. The temperature control door 751 in the air conditioning case 750 at the time of maximum heating operates so as to close the passage bypassing the heater core 760 so that the air blown into the air conditioning case 750 by the blower is supplied to the heater core 760, And is supplied to the inside of the car, thereby heating the inside of the car.

The high-temperature and high-pressure gaseous refrigerant compressed and discharged by the compressor 700 passes through the water-cooled condenser 800 via the direction switching valve 781, and heats the cooling water passing through the water-cooled condenser 800. The refrigerant condensed in the water-cooled condenser 800 expands through the second expansion means 721, passes through the chiller 740, recovers the engine waste heat, and then circulates back to the compressor 700.

In this case, the cooling water heated by the water-cooled condenser 800 performs the indoor heating by heat-exchanging with the air through the heater core 760. That is, the cooling water passing through the water-cooled condenser 800 passes through the heater core 760 along the second cooling water lines 703 and 705, bypasses the chiller 740 and the engine 761 by the four-way valve 706, Is circulated to the condenser (800). On the other hand, the cold water flowing in the first cooling water line 704 circulates through the engine 761, the chiller 740, and the engine 761. In the above, the heater core 760 of the second cooling water line serves as a heat generating portion, and the chiller 740 of the first cooling water line serves as a heat absorbing portion.

FIG. 7 illustrates a heating heat pump mode and a dehumidifying mode of a vehicle air conditioning system according to an embodiment of the present invention.

Referring to FIG. 7, the refrigerant is circulated along the second refrigerant circulation line 702 under the control of the directional control valve 781. The temperature control door 751 in the air conditioning case 750 at the time of maximum heating operates so as to close the passage bypassing the heater core 760 so that the air blown into the air conditioning case 750 by the blower is supplied to the heater core 760, And is supplied to the inside of the car, thereby heating the inside of the car.

The high-temperature and high-pressure gaseous refrigerant compressed and discharged by the compressor 700 passes through the water-cooled condenser 800 via the direction switching valve 781, and heats the cooling water passing through the water-cooled condenser 800. The refrigerant condensed in the water-cooled condenser 800 expands through the second expansion means 721, passes through the chiller 740, recovers the engine waste heat, and then circulates back to the compressor 700.

At this time, a part of the refrigerant flowing to the chiller 740 flows selectively to the refrigerant branch line 910 by the operation of the refrigerant flow rate control valve 920, so that the refrigerant flowing from the first expansion unit 720 to the indoor heat exchanger 710 1 refrigerant circulation line 701 and flows to the indoor heat exchanger 710 side. The expanded refrigerant undergoes heat exchange with the air in the air conditioning case 750 while passing through the indoor heat exchanger 710 and condenses the moisture in the air on the surface of the indoor heat exchanger 710 to perform dehumidification.

The air conditioning system for a vehicle according to an embodiment of the present invention can perform the dehumidifying action by simultaneously flowing low temperature and low pressure refrigerant to the indoor heat exchanger while heating the cooling water through the water-cooled condenser. Therefore, the air conditioning exhaust power can be reduced by branching the low-pressure refrigerant to the chiller and the indoor heat exchanger without driving the high-voltage PTC and the cooling cycle (compressor drive) even during the heating mode operation.

In addition, since the refrigerant branch line is branched upward from the second refrigerant circulation line, which is the heating line, the refrigerant branching direction is always formed as an upper part, thereby preventing the oil circulating in the refrigerant line from being accumulated in the branch line.

While the vehicle air conditioning system according to the present invention has been described above with reference to the embodiments shown in the drawings, it is to be understood that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the scope of the true technical protection should be determined by the technical idea of the appended claims.

700: compressor 710: indoor heat exchanger
720: first expansion means 721: second expansion means
730: outdoor heat exchanger 740: chiller
750: air conditioning case 751: temperature control door
760: Heater core 770: Accumulator
781: Directional valve
701: first refrigerant circulation line 702: second refrigerant circulation line
704: first cooling water line 703, 705: second cooling water line
706: Four-way valve 800: Water-cooled condenser
810: Heating means 910: Refrigerant branch line
920: Refrigerant flow control valve

Claims (11)

A compressor 700 for compressing and discharging the refrigerant;
An indoor heat exchanger (710) provided inside the air conditioning case (750) for exchanging heat between air and refrigerant;
An outdoor heat exchanger 730 provided outside the air conditioning case 750 for exchanging heat between the outdoor air and the refrigerant;
A heater core 760 provided inside the air conditioning case 750 to exchange heat between air and cooling water;
A first expansion means (720) provided between the indoor heat exchanger (710) and the outdoor heat exchanger (730) for expanding the refrigerant;
A chiller 740 for exchanging heat between the waste heat of the vehicle and the refrigerant;
A water-cooled condenser 800 for exchanging the refrigerant discharged from the compressor 700 with the cooling water in the cooling water line flowing through the heater core 760;
The refrigerant discharged from the compressor 700 is circulated through the first refrigerant circulation line 730 connected to the refrigerant line so as to circulate the outdoor heat exchanger 730, the first expansion device 720, the indoor heat exchanger 710, (701); And
And a second refrigerant circulation line 702 connecting the refrigerant line to circulate the refrigerant discharged from the compressor 700 to the water-cooled condenser 800, the chiller 740, and the compressor 700,
And a part of the refrigerant in the second refrigerant circulation line (702) branches to the first refrigerant circulation line (701). The method according to claim 1,
And a second expansion means (721) provided in the second refrigerant circulation line (702) between the water-cooled condenser (800) and the chiller (740) for expanding the refrigerant,
A refrigerant branch line 910 branched from the second refrigerant circulation line 702 downstream of the second expansion means 721 to flow at least a part of the refrigerant flowing toward the chiller 740 side toward the indoor heat exchanger 710 side, The air conditioning system comprising: 3. The method of claim 2,
Wherein the refrigerant branch line (910) connects the refrigerant line between the second expansion means (721) and the compressor (700) to the front end of the indoor heat exchanger (710). 3. The method of claim 2,
And a refrigerant flow rate control valve (920) for selectively controlling the amount of refrigerant flowing toward the refrigerant branch line (910). 3. The method of claim 2,
The refrigerant branch line 910 is branched between the second expansion means 721 and the chiller 740 and flows through the first refrigerant circulation line 701 between the first expansion means 720 and the indoor heat exchanger 710, To the air conditioning system. 3. The method of claim 2,
And the refrigerant branch line (910) is connected upward from the second refrigerant circulation line (702). 3. The method of claim 2,
A first cooling water line 704 which is a passage for connecting the engine 761 of the vehicle with the chiller 740 so as to cool the cooling water;
A second cooling water line connected to the first cooling water line 704 for selectively passing or bypassing the first cooling water line 704 and circulating the heater core 760; And
And a four-way valve 706 connecting the first cooling water line 704 and the second cooling water line,
Wherein the cooling water passing through the heater core (760) passes or bypasses the chiller (740) and the engine (761) according to the operation of the four-way valve (706). 8. The method of claim 7,
Wherein the second cooling water line is provided with a heating means (810) for heating the cooling water. 8. The method of claim 7,
The refrigerant discharged from the compressor 700 is discharged to the first refrigerant circulation line 701 or the second refrigerant circulation line 703 at the point where the first and second refrigerant circulation lines 701 and 702 are branched at the outlet side of the compressor 700, And a direction switching valve (781) for switching the refrigerant flow direction so as to flow toward the second refrigerant circulation line (702). 3. The method of claim 2,
The refrigerant discharged from the compressor 700 circulates through the outdoor heat exchanger 730, the first expansion device 720, the indoor heat exchanger 710, and the compressor 700,
Wherein the refrigerant discharged from the compressor (700) circulates through the water-cooled condenser (800), the second expansion means (721), the chiller (740), and the compressor (700) in the heating mode. 3. The method of claim 2,
In the dehumidifying mode, a part of the refrigerant discharged from the compressor 700 and flowing to the chiller 740 through the water-cooled condenser 800 and the second expansion means 721 flows selectively to the refrigerant branch line 910, (710). ≪ / RTI >

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